Lifting jack



March 5, 1929. 1.. PERKINS 1,704,148

LIFTING JACK Filed Sept. 5, 1925 5 mm Z i Imanior LeflierfezJzinp,

jj rM aw 73% Patented Mar. 5,1929. 1,704,148 UNITED STATES PATENT OFFICE.

LESTER PERKINS, OF CHICAGO, ILLINOIS, ASSIGNOR TO YELLOW JACK-IT MANUFAC- TUBING 00., A. CORI'ORATION OF ILLINOIS.

mrrmo JACK.

Application filed September 5, 1925. Serial No. 54,601.

This invention relates to lifting jacks for automobiles and the like and is particularly directed to the improved lifting mechanism thereof.

Ii In connection with lifting jacks of the con-, struction hereinafter described, it has been found necessary in some cases to provide a means whereby the axle of the car being raised may be elevated beyond the maximum height permittedb the jack when in its extended position. I n other words, by reason of the variation in the heightof the axle above the ground in various types of automobiles it has been found convenient to provide an extension which will permit the showing the main frame of the jack in cross section.

Fig. 3 is a front elevational view of the lifting mechanism showing the main frame in cross section with the extension positioned thereonfor elevating the lifting cradle.

Figs. 4 and 5 are enlarged to plan'and side elevational views, respective y, of the. extension member, and

Figs. 6 and 7 are enlarged top plan and slde elevational views, respectively, of the cradle supporting member.

The jack illustrated in the drawing is substantially of the same form as shown in 00- pending application Serial No. 504 filed J ancradle to be supported in the position above its maximum low position so that when the lifting mechanism is elevated to its maximum high position the axle of the car will be raised above the normal maximum high position of the lifting mechanism.

One of the objectsof the present invention is to provide an improved form of cradle supporting structure which is especially adapted for maintaining the cradle in a horizontal position during the movement of the lifting mechanism from its extreme low position to its extreme high position.

- A still further object of the invention is to provide an improved form of extension which is attached to the lifting mechanism in a manner that the same may be placed in position for supporting the cradle for elevating the maximum low and maximum high positions of the lifting mechanism.

The invention hereinafter described is an improvement on the construction shown in,

copending applications Serial Nos. 684,283, filed January 4, 1924 and 504, filed January 5,1925, both of which are in the name of Andrew J. and Lester Perkins.

The above and other objects are accomplished by providing a construction and an arrangement of the various parts in the man ner hereinafter described and particularly pointed out in the appended claims.

Referring to the drawings, Fig. 1 is a side elevational view showing a portion of a lifting jack and particularly the lifting mechanism thereof in its extended or maximum high position having my improvement embodied therein.

Fig. 2 is a side elevational view of the mechanism shown in Fig. 1 with the lifting mechanism in its maximum'low position and 18 to permit the free end thereof to freely nary 5, 1925, and com rises a main frame 10 which is substantia ly'in the form of a channel and is provided with the usual axle 11 and carrying wheels 12 on the opposite sides of the frame. Secured on the opposite sides of the main frame 10 by means of bolts 13 are oppositely disposed side plates 14 .which extend forwardly, the forward end of these side plates being supported on castor wheels in the manner. illustrated and described in the above last named application. Pivoted to the main frame 10 on the bolt 13 extending through the side plates 14 are main lifting members or links 15. Pivoted intermediate the ends of the main lifting members 15 by means of atransverse pin 16 is a pair of supplemental lifting members 17. The lower or free ends of the supplemental lifting members 17 are provided with a roller traverse the bottom portion of the main frame 10. The upper ends of the supplemental lifting members 17 are provided with right angnlarly extending arms 19 giving these members a. substantially L shaped 2 form. Pivoted tothe upper ends of the main lifting members 15 and supplemental lifting members 17 by means of transverse pins 20 and 21 are two pairs of co-operating lifting members or links 22 and 23, respectively. The upper ends of the co-operating lifting members or links 22 and-23 are pivotally connected together by a. common pin 24 which in turn pivotally supports between the opposite pairs of these co-operating links 22 and 23 one end of a cradle supporting member 25. The other endof the cradle supporting member 25 is pivotally connected by means of a pin 26 and a pair of links 27 the free end no of the arm 19 of the supplemental lifting member 17 The links 27 are pivotally secured to the inside of the arm 19 by means of countersunk pins 28.

From the above description it will be read ily understood that as the lifting mechanism is actuated from its lowermost position or the position shown in Fig. 2 to its maximum high position, or-the positionshown in Fig. 1, that the cradle supporting member will be maintained in substantially a horizontal position throughout its entire movement and thereby maintain a cradle 29 which is swivelled in an aperture 30 adjacent the pin 24 also in substantially horizontal position throughout the movement of the lifting mechanism. 1

Another essential feature of my improved invention is the provision of an easily manipulated device for affordingan extension or elevatlon of the lifting cradle. This comprises an extension member 31 having a barrel portion 32 formed on one end thereof with a cylindrical socket 33 extending longitudinally of the barrel portion. grally with the barrel portion of the extension member are two laterally extending spaced apart arms 34. The outer ends of the arms 34 are provided with aligned apertures 86 for pivotally securing the extension member 31 to the pin 26, forming the pivotal connection between the cradle support 25 and the ing the .axle ,ofthecar. When the extensioni member is in its inoperative position it moves upwardly and downwardly-with the lifting V (cradle: in a substantially, horizontal posit on tion of'theijack, but is soarran'ged'tha't the rthroughoutthe entire movement of sa d l ftqingineinbers, and means-pivoted to said liftand in the full lines in Fig.3.

links 27. One end of the barrel portion 32 of the extension member 31 is provided with a circular boss 37 which 'is adapted to be-seated in the aperture 30 in the cradle supporting member 25 when the extension member3l is swung into its position for extending the cradle as shown in the dotted lines in Fig.1

From the above description itvwill beread .ily understood that when the-operator-is not desirousof employing the extension member]; 31 for elevating the cradle 29 it maybe swung into its inoperative position or in the fullline position shown in Figs. 1 tion the cradle 29 with its verticallyprojectis positioned in the aperture .30 of the cradle supporting member 25 and the ing shank 29 lifting mechanism may be actuated for elevatmechanismas the same is movedin the opera lower end of theexten'sionf member 31 engagesthe upperside of the connecting links ture 30 in the cradle supporting-member 25 and the extension member is swung into its' ed by Formed inte and 2. In this posi-- bers pivoted to each of the aforesaiflifting which are pivotally connected to the freeend of the supplemental lifting member 17 by a pin 39 which also pivotallyconnects the roller 18 to these members. The other ends of the connecting links 38 are operatively connectmeans of a chain to an'operating lever and winding drum mechanism of the construction shown and described in the co-pending application last referred to.

While in the above specification .I have de-. scribed one form of my invention, it will of course be understood that modification'may be made without departing from the spirit and scope of the invention as expressed in the following claims. w h V V I What'I claim as my inventionand desire to secure by Letters Patent is: i

-1. A lifting jack comprising a mainframe, a lifting mechanism including a lifting member pivoted to said'm'ainframe, a supplemental lifting member pivoted to said first named supporting member and to said supplemental lifting member for maintaining said cradle :in substantially horizontal position through- ,out' the entire movement of said lifting mem:

p 2. Alifting jack comprising a main frame, aliftlng mechanism including alifting member pivotedtosaid mam frame, a supplemental lifting member pivoted to said first namedlifting member, co-operating lifting members pivoted to eachvof the aforesaid lifting members, a cradlesupporting member piv- 'oted to said cooperating lifting members, a cradle; swivelled in said crad1e.support1ng member, a link pivotally conneoted' to said...

cradle supporting member'and to said supplemental. lifting"memberv for maintaining said ,ing mechanism 7 for extendin the position ber pivoted to said main frame, a supp emental lifting member pivoted to said first named lifting member, co-voperating lifti memlit? members, a cradle supporting member pivoted to said ecu-operating lifting members, a cradle swivelled in said cradle supporting member, a link pivotally connected to said cradle supporting member and to said supplemental lifting member for maintaining said cradle in a substantially horizontal position throughout the entire movement of said lifting members, and means carried by said lifting mechanism for extending the normal position of said lifting cradle above said c 'adle supporting member.

4. A lifting jack comprising a main frame, a lifting mechanism including a lifting member pivoted to said main frame, a supplemental lifting member pivoted to said first named lifting member, co-operating lifting members pivoted to each of the aforesaid lifting members, a cradle supporting member pivoted to said co-operating lifting members, a cradle svvivelled in said cradle supporting member, a link pivotally connected to said cradle supporting member and to said supplemental lifting member for maintaining said cradle in a substantially horizontal position throughout the entire movement of said lifting members. and means movably mounted and adapted to be seated on said cradle supporting member for normally extending the position of said cradle above said cradle supporting member.

5. A lifting jack comprising a frame, lifting mechanism mounted on said frame including a liftin member, a supplemental lifting member pivoted intermediate the ends of said lifting member, an arm extending laterally from said supplemental lifting member, co-operative lifting members pivoted to the upper ends of said lifting member and said supplemental lifting member. a cradle supporting member having one end thereof pivoted to said co-operativo lifting members, a cradle swivelled in the cradle supporting member, and a link pivotally connecting one of the ends of said cradle supporting member to said arm for normally maintaining said cradle in substantially horizontal position throughout the entire movement of said lifting mechanism.

6. A lifting jack comprising a frame, a lifting mechanism mounted on said, frame comprising a plurality of lifting members pivoted to said frame. supplemental L-sbaped lifting members pivoted intermediate the ends of said first named lifting members, a roller journalled on the lower end of said supplemental lifting members for traversing said main frame. cooperating lifting members pivoted'to the upper ends of said first named lifting members and said supplemental lifting members, a 0 mile supporting member pivoted to said co-operating lifting members and extending forwardly therefrom, a c 'adle swivelled on said cradle supporting member. and a plurality of links pivotally connected to the forward end of said cradle supporting member and to said L- shaped members for normally maintaining said cradle in substantially horizontal position throughout the entire movement of said lifting mechanism.

7. A lifting jack comprising a frame, a lifting mechanism mounted on said frame comprising a plurality of lifting members pivoted to said frame, supplement L-shaped lifting members pivoted intermediate the ends of said first named lifting members, a

tion throughout the entire movement of said lifting mechanism, and an extension member pivoted to said cradle supporting member and adapted to be seated on said cradle supporting member for normally extending the position of said cradle above said cradle supporting member.

8. A lifting jack comprising a main frame, a lifting mechanism including a lifting member pivoted to said frame, a supplemental lifting member pivoted to said first named lifting member, cooperating lifting members pivoted to each of the aforesaid lifting members, a cradle supporting member operatively connected with said cooperating lifting members, a cradle swivelled in said cradle supporting member, and means connected to said cradle supporting member and with said supplemental lifting member for maintaining said cradle in a substantially horizontal position throughout the entire movement of said lifting members.

In testimony WhereofI have signed my name to this specification, on this 2nd day of September A. D. 1925.

LESTER PERKINS. 

